Monday Gantt – Dark Mode Hack Demo

body {
margin: 0;
background: #0a0a0a;
font-family: system-ui, sans-serif;
color: #ddd;
}

.header {
padding: 14px 18px;
background: #111;
border-bottom: 1px solid #222;
font-size: 15px;
display: flex;
justify-content: space-between;
align-items: center;
}

.toggle-btn {
cursor: pointer;
padding: 6px 14px;
font-size: 13px;
border: 1px solid #333;
border-radius: 4px;
background: #1c1c1c;
color: #eee;
transition: .15s;
}
.toggle-btn:hover {
background: #333;
}

.gantt-wrapper {
width: 100%;
height: calc(100vh – 48px);
background: #000;
overflow: hidden;
}

iframe {
width: 100%;
height: 100%;
border: 0;
/* Default: dark mode ON */
filter: invert(1) hue-rotate(180deg) brightness(.92) contrast(.96) saturate(.85);
transition: filter .25s ease-out;
}

/* Light mode class just removes filter */
.light iframe {
filter: none;
}

function toggleMode() {
document.getElementById(“wrap”).classList.toggle(“light”);
}